• Journal of Advanced Marine Engineering and Technology
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• 제29권2호
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• pp.177-184
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• 2005

Experimental studies on the characteristics of ice slurry flows in a circular pipe is rare due to the deficiency of conventional measurement techniques. In this report the flow characteristics are quantitatively investigated by the use of PIV technique concerning the Ice Packing Factor(IPF) and the power changes of pump motor It was experimentally verified that the power loss does not increase any more at a certain IPF value.

• 한국전자통신학회논문지
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• 제14권3호
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• pp.497-504
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• 2019

본 연구에서는 고주파 마그네트론 스퍼터링 법을 이용하여 $HfO_2$ 박막을 제작하고, 질소 분위기에서 급속 열처리 온도에 따른 $HfO_2$ 박막의 구조적 및 광학적 특성을 조사하였다. XRD 측정을 통해 열처리 유무에 상관없이 $HfO_2$ 박막은 다결정 구조를 가짐을 확인할 수 있었고, 열처리 온도가 증가함에 따라 반가폭은 감소하는 추세를 나타내었다. 박막의 표면을 AFM 으로 조사한 결과, $600^{\circ}C$ 에서 열처리한 박막의 표면 거칠기가 3.454 nm 로 가장 작은 값을 나타내었다. 모든 $HfO_2$ 박막들은 가시광 영역에서 약 80% 정도의 투과도를 나타내었다. 또한 투과도와 반사도로부터 구한 굴절률과 셀마이어 분산 관계로부터, 파장에 따른 $HfO_2$ 의 굴절률을 예측할 수 있었다. $600^{\circ}C$ 에서 열처리 한 $HfO_2$ 박막이 2.0223 (${\lambda}=632nm$) 의 높은 굴절률과 0.963 의 높은 우수한 충진율을 나타내었다.

• 멤브레인
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• 제25권3호
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• pp.268-275
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• 2015

침지식 분리막 모듈에서 공기강도에 따른 분리막 위치에 대한 오염을 조사하였다. 분리막의 충진밀도가 낮은 곳에서 높은 유체 유속을 나타내었으며, 유체 속도는 기-액 주입률에 비례하였다. 전단응력은 기-액 주입률 및 유체 유속에 비례하였다. 비가역오염($R_{ir}$)은 흡입 압력이 가까운 부분에서 가장 높게 나타났다(position 1). 비가역오염에 대한 저항과 분리막 고유 저항의 비($R_{ir}/R_m$) 및 비가역오염에 대한 저항과 가역오염의 저항의 비($R_{ir}/R_r$)도 position 1에서 가장 높게 조사되었다. 비가역오염($R_{ir}$)은 흡입 압력이 높은 곳인 position 1에 오염물질이 축적되어진 결과이다. 분리막 위치에 따른 오염현상은 모듈 디자인 최적화에 중요한 인자임을 알았다.

• Elastomers and Composites
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• 제52권4호
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• pp.317-325
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• 2017

Molding conditions can be described as factors that determine the quality of a product obtained from injection molding. Many studies have been performed on the injection molding pressure, injection temperature, packing pressure and other molding conditions related to part quality. However, the most accessible factor among the adjustable molding conditions during actual injection is the injection speed. In this study, we simulated the variation of the physical quantity according to injection speed and performed experiments to understand the effect of injection speed on the actual product. A CAE analysis program (Moldflow) was used to simulate and analyze the results using PC and PBT for two models. In order to compare these results with the experimental results, an actual injection molding was performed for each injection speed, and the correlation between simulation and injection molding, especially for the shrinkage of the molded article, was discussed.

• 한국연초학회지
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• 제13권1호
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• pp.61-68
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• 1991

The moisture contents of threshed leaf tobacco during aging storage were very important factor for the improvement or deterioration of leaf quality. Decay and carbonization of leaf tobacco were mainly controlled by moisture contents during storage. The influence of moisture contents on the decay and carbonization of threshed leaf tobacco (Flue-Cured, Var. NC 82. AB3O-1 grade) were examined during 1 year. The moisture contents of leaf tobacco were treated to 3 kg as 12% (controle), 16%, 20% and 24% after redrying, respectively, These tobacco were put into center of carton box containing about 200kg with 12%'s tobacco, and then packed and stored from June, 1988 under natural weather condition in warehouse at Ock-Cheon threshing plant. Samples were taken from dissected carton box at 0, 1, 2, 4, 7 and 12 months after moisture treatment and Racking time, and some chemical properties were investigated at every sampling time. In results of inducement to decay and carbonization of leaf tobaccos during 1 year's storage by moisture treatment. decayed leaf was appeared but carbonized leaf did not. Calorification and decayed leaf occurred at high moisture contents above 20%, and these phenomena were appeared between 30 and 150 days after moisture treatment and packing. High moisture content leaves (above 20%) caused nearby other leaves to be sunk with high moisture content. Nicotine and calcium contents were increased to 20%~30% and 10%~22%, respectively, but total sugar contents was decreased to 40%~60% by moisture treatment(20% ~24% ).

• Journal of Advanced Marine Engineering and Technology
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• 제27권2호
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• pp.272-279
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• 2003

This study aimed to understand the effects of transporting ice slurry Particles through Pipes with branches. The experimental apparatus was constructed as ice slurry mixing tank. vortex pump, manometers for differential pressure measuring. IPF(ice packing factor) measuring instruments and branches as test sections. The experiments were carried out under various conditions. with concentration of water solution ranging between 0∼20wt% and velocity of water solution at the entry ranging between 1.5∼2.5m/s. The differential Pressure and IPF between the pipe entry and exit were measured. and flowing form was checked throughout the experiment. The pressure loss in 3d branches appeared compared with 6d branches so that it was very high. In the pressure loss of the inside and outside of branches. 6d branches was showed the difference. but was agreed in 3d branches The pressure loss according to concentration of water solution, low value appeared at 10wt% in 6d branches, at 20wt% in 3d branches. The pressure loss according to velocity, did not show large difference. The change of IPF at outlet, appeared +15∼-25% in 6d branches and 0∼-20% in 3d branches. The difference of IPF at the inside and outside of branches. appeared 10∼15% in 6d branches and maximum 5% in 3d branches.

• 태양에너지
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• 제18권1호
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• pp.99-109
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• 1998

공기조화 설비에 있어서 시스템의 성능을 향상시키고 에너지의 유효이용 및 경제성을 높일 수 있는 빙축열 시스템에 대한 연구이다. Ice Ball을 내장한 빙축열조를 횡형 사각형과 입형 원통형 축열조에 대하여 조내로 유입하는 브라인의 유량(2, 4, 6LPM)과 온도(-3, -5, $-7^{\circ}C$)를 변화시키고, 또한 유입 브라인의 유동을 상 하향유동으로 하면서 빙축열조내의 온도분포를 파악하여 열유동 특성 및 빙충전율에 대하여 고찰하였다. 연구결과 빙축열조내 열성층을 향상시키기 위해서는 조내 유입 브라인의 유동이 상향 압출흐름이어야 한다는 것을 알았다.

• 동아시아식생활학회지
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• 제15권3호
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• pp.247-256
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• 2005

This study was performed by questionnaire to investigate the preference for Korean traditional foods and revisiting intentions of Japanese tourists. The Subjects were consisted of 280 Japanese tourists staying at Gyeongju and Busan area. The results of this study were as follows: Among the respondents, $61.1\%$ selected 'taste' as the most important factor affecting the preference for korean traditional foods. On the frequency of eating, 'over 8 times per year' scored as high as $27.9\%$. The motivation of eating Korean foods was answered as 'With visiting Korea' by $48.2\%$ Thirties and forties ate Korean traditional foods more often than the others did $61.8\%$ of the Japanese tourists intended to eat more Korean traditional foods in the future. But the necessity of hygienic improvement was pointed out by $32.1\%$ of the subjects. Male subjects wanted the improvement of nutrition, taste and storage, while females shape, color and packing. The preferred Korean traditional foods were 'Bulgogi', 'Kimgui', 'BaechooKimchi', 'Bibimbap', and 'Samgaetang' in the order. On the other hand, the preference for 'Soojeongkwa', 'Songpeon', 'Kalgooksoo', 'Injelmi' and 'Sikhye' was very low. Male subjects favoured 'Cholbap', 'Ogokhap', and 'Youkgaejang', while females liked better 'Oisobaki' and 'Ddukboki. The people who were over fifties preferred 'Ssalbap', 'Boribap', 'BaechooKimchi', and 'Ggakdugi' and forties liked 'Kongbap' and 'Kimhap' better. The most effectual food items provoking revisiting intention to Korea were 'Jeon', and 'Bap', 'Meon' and 'Jjigae' were ranked in next.

• Applied Microscopy
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• 제46권2호
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• pp.105-109
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• 2016

Palladium has been used as a catalyst not only in Suzuki and Heck cross coupling reaction in organic chemistry, but also in automobile industry for the reduction of vehicle exhausts. The catalytic activity of Pd nanoparticles depends strongly on their size and exposed crystalline facets. In this study, the single crystalline palladium nanocubes/nanorods were prepared in the presence of polyvinyl pyrrolidone (PVP) and potassium bromide (KBr) using the polyol method. Selected area diffraction pattern and high-resolution transmission electron microscopy (TEM) were performed by TEM. The result shows that the ratio of KBr/PVP is the key factor to determine whether the product is cubes or rods. The as-prepared Pd nanocubes were highly uniform in both size and shape. The ordered packing structures including monolayer and multilayer can be fabricated via the rate-controlled evaporation of solution solvent. The catalytic activity of these Pd nanocubes towards heck reaction of iodobenzene with acrylate or acrylic acid was found to be higher than that of Pd nanorods. We suspect it is caused by the difference of energy state while Pd nanocubes is {100} plane and nanorods is {111} plane.

• 한국조리학회지
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• 제14권2호
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• pp.115-127
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• 2008

The purpose of this study is to validate the evaluation of stock, which has relation with self-esteem and career for the development of commercial stock. This study conducted a survey of purchasing attitudes & receptiveness in order to hold an accurate course for developing stock. According to the analysis, the results are as follows. It examined the cuisiniers of deluxe hotels who mainly use stock of Seoul and the capital region. A total of 350 samples were distributed and 289 samples were selected for the research. Statistical analysis of collected data executed frequency, percentage, average, reliability analysis, factor analysis using SPSSWIN 12.0 PC package programs. Making stock, cooking skills, cooking methods, quality of food ingredients and cooking recipes are important. Also, sensory characteristics such as color, odor, and taste should be considered. Career and self-esteem act on the purchase accommodation attitude of commercial stock. Commercial stock products more than 1,000 mL or 2,000 mL of liquid styles need packing of vacuum pack(vinyl). Based on the result of this study, we will make efficient use of research data for the development of commercial stock products and we will be able to improve conservation of taste with good quality by making by hand through standardization and mass production of traditional culinary skills.